Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
  1. GRB 110402A: NOT afterglow confirmation
  2. GRB 110402A: Liverpool Telescope Observations
  3. GRB 110402A: Swift detection of a burst
  4. GRB 110328A / Swift J164449.3+573451: KASINICS NIR Observation
  5. GRB 110328A / Swift J164449.3+57345: Correction to GCN 11850
  6. GRB 110328A / Swift J164449.3+573451: Radio-optical/NIR Astrometry
  7. GRB 110328A / Swift J164449.3+573451: Infrared transient
  8. GRB 110328A / Swift J164449.3+573451: Mondy optical observations
  9. GRB 110328/Swift J164449.3+573451: Fermi observations
  10. GRB 110328A / Swift J164449.3+573451: KASINICS K-band Observation
  11. GRB 110328A / Swift J164449.3+573451
  12. GRB 110328A / Swift J164449.3+573451: EVLA observations of a brightening radio source
  13. GRB 110328A / Swift J164449.3+573451: X-ray analysis and a mini-blazar analogy
  14. GRB 110328A / Swift J164449.3+573451: Gemini and UKIRT IR observations
  15. GRB 110328A / Swift J164449.3+573451: PAIRITEL NIR Detection in 2nd Epoch
  16. GRB 110328A / Swift J164449.3+573451: No optical variability of the optical counterpart
  17. GRB 110328A / Swift J164449.3+573451: beamed emission
  18. GRB 110328A / Swift J164449.3+573451: BAT refined analysis
  19. GRB 110328A / Swift J164449.3+573451: CARMA mm detection
  20. GRB 110328A / Swift J164449.3+573451: Konkoly observations
  21. GRB 110328A / Swift J164449.3+573451: LOAO R-band Observation
  22. GRB 110328A / Swift J164449.3+573451: PAIRITEL NIR Upper Limits
  23. GRB 110328A / Swift J164449.3+573451: optical observations
  24. GRB 110328A / Swift J164449.3+573451: EVLA Detection
  25. GRB 110328B: Fermi-LAT Detection
  26. GRB 110328A / Swift J164449.3+573451: optical spectroscopy from GTC
  27. GRB 110328A: Gemini spectroscopic observations
  28. GRB 110213A, the review of the sky area in plate archives
  29. GRB 110328B: Fermi GBM detection
  30. GRB 110328A / Swift J164449.3+573451: NOT optical observations.
  31. GRB 110328A/ Swift J164449.3+573451 : Xinglong TNT Upper limit
  32. GRB / X-ray transient 110328A: MITSuME OkayamaOptical upper limits
  33. GRB 110328A / Swift J164449.3+573451: PTF Quiescent Optical Counterpart
  34. GRB 110328A: Enhanced Swift-XRT position
  35. GRB / X-ray transient 110328A: Gemini optical observations
  36. GRB 110328A: a second trigger, probably a hard X-ray transient (Swift J164449.3+573451)
  37. GRB 110328A: Swift detection of a burst
  38. GRB110318B : MOA optical upper limit
  39. Fermi Gamma-ray Burst Monitor trigger 322686470 (110324797) is not a GRB
  40. GRB 110319B Swift-XRT afterglow confirmation
  41. GRB 101225A: revised analysis of narrow band imaging
  42. GRB 110319B BAT refined analysis
  43. GRB 110319B: Swift/UVOT Upper Limits
  44. GRB 110318B: Swift/UVOT Upper Limits
  45. GRB 110319B: GROND upper limits
  46. GRB 110319B: Swift-XRT afterglow candidate.
  47. GRB 110319B found in ground analysis of Swift-BAT data
  48. GRB 110319A: Swift/UVOT Detection
  49. GRB 110319A: Swift-BAT refined analysis
  50. GRB 110319A: Swift-XRT refined Analysis
  51. GRB 110318B: GROND upper limits
  52. GRB 110319A: Enhanced Swift-XRT position
  53. GRB 110319A: Swift detection of a burst
  54. GRB 110318B: Swift-XRT refined Analysis
  55. GRB 110318A: Fermi GBM detection
  56. GRB 110318B: Swift-BAT refined analysis
  57. GRB 110318B: Enhanced Swift-XRT position
  58. GRB 110318A: Swift-BAT refined analysis
  59. GRB 110318B: Swift/UVOT Non-Detection of an Afterglow
  60. GRB 110318B: Swift detection of a burst
  61. GRB 110318A: Swift detection of a burst
  62. Fermi GBM trigger 321944155 (110316205) is not a GRB
  63. GRB 110315A: RTT150 optical observations
  64. GRB 110315A: Swift/UVOT Upper Limits
  65. GRB 110315A: Swift-XRT refined Analysis
  66. GRB 110315A: Swift-BAT refined analysis
  67. GRB 110315A: Enhanced Swift-XRT position
  68. GRB 110315A: MASTER early optical observations
  69. GRB 110315A: Swift detection of a burst
  70. GRB110312A: MITSuME Okayama Optical upper limits
  71. GRB 110312A: RTT150 optical observations
  72. GRB 110312A: Swift/UVOT Upper Limits
  73. GRB 110312A: Swift-XRT refined Analysis
  74. GRB 110312A: GROND Upper Limits
  75. GRB 110312A: Enhanced Swift-XRT position
  76. GRB 110312A: Swift-BAT refined analysis
  77. GRB 110312A: Swift detection of a burst
  78. GRB 110305A: REM detection of a possible NIR afterglow
  79. GRB110305A: MITSuME Ishigakijima Optical upper limits
  80. GRB 110305A: Swift/UVOT Upper Limits
  81. GRB 110305A: Swift-XRT refined Analysis
  82. GRB 110305A: Enhanced Swift-XRT position
  83. GRB 110305A: Swift-BAT refined analysis
  84. IBAS trigger n. 6138 is not a GRB
  85. GRB 110305A: GROND Detection of Optical Afterglow
  86. GRB 110305A: Swift detection of a burst
  87. GRB 110223A: optical upper limits
  88. GRB 110301A: Fermi GBM detection
  89. GRB101225A: early EVLA Observations of Christmas Burst
  90. Swift/UVOT observations of GRB110223A
  91. No IPN GRB detected in conjunction with candidate GRB 110215
  92. GRB GRB 110223A: MASTER VWF early optical observations
  93. IBAS distribution of coordinates for low significance INTEGRAL GRB triggers
  94. Swift/UVOT observations of GRB110223b
  95. GRB 110223A: Swift-BAT refined analysis
  96. GRB 110223A : early optical limit by "Pi of the Sky"
  97. GRB 110223A: Liverpool Telescope observations
  98. GRB 110223A: Swift-XRT refined Analysis
  99. GRB 110223B: Swift-XRT refined Analysis
  100. GRB 110223A: Enhanced Swift-XRT position

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov